The invention primarily concerns a temperature conditioning support for thermal tests on small objects such as semiconductor wafers containing integrated circuits, comprising an platen and a base which receives the platen, the two elements being conformed so that once assembled they leave an internal cavity, inside which can flow a thermal fluid capable of heating and/or cooling the platen in view of providing the temperature regulation of the object placed on the platen, according to data supplied by thermometric system that includes a temperature sensor associated to said support.
Temperature conditioning supports of the type considered are used in connection with probe testing apparatus for integrated circuits on wafers or chips or similar electronic components such as hybrid circuits. The component under test is placed on the support which has the dual function of bringing and maintaining the component at a predetermined control temperature and of positioning the component extremely accurately with respect to the test probes, using an ajustable mechanical platform.
Known temperature conditioning supports usually employ an aluminimum platen. This introduces many drawbacks: it is difficult to produce aluminium workpieces that meet tight tolerances, even with careful and costly machining operations. Moreover, aluminium is prone to thermally induced deformations, which upset the support's mechanical stability. Also, because of the relative softness of aluminium, successive dismantling and reassembly of the support cannot be performed without having to remachine the constituent elements. Furthermore, aluminium being a metal, it is difficult to obtain high insulation resistance with a metal platen which, besides, produces a high stray capacitance which can affect the quality of electrical measurements carried out on the electronic components.
In addition, such a temperature conditioning support should provide high precision not only from the mechanical and dimensional point of view, but also as concerns temperature regulation uniformity and tolerances. Yet, the required regulation characteristics are difficult to achieve with an aluminium support platen.